If you are going to set a drop-in tub into a deck which is already tiled, do you hold the tub up off of the tile deck by 1/16 inch or 1/8 inch to allow for caulk to go under the lip? If so do you recommend using paint sticks or something as spacers to help set the tub flat with an even gap? Or no gap is required?

I would thick you would want a gap so the weight of the tub and water is carried by the mortar bed and not the lip. I think Kohler requires or recommends a gap. In practice is this really done?

I agree. But it’s been my experience that the tub is typically set prematurely in an effort by the plumber to finish their work with zero consideration to the tiling trade. The only times I’ve seen the tub being set down into the deck tile has been when I’m the general contractor.

If the valves are installed in the tub deck, depending on where they are located, that may have to be done before the tub is dropped in the hole. I would avoid putting the spout in the back. You want to be able to feel the water as the tub is filling without stepping in the tub. Kinda common sense but something that's not always thought about.

Yeah, the skirt may have to be left open to solder pipes and to hook up the drain. At least an access opening.

I have a 42 inch wide soaking tub ordered. Originally I was thinking my deck should be, could be, would be 48 inches wide. Now I am looking at tile and particularly 12 x 12 or 24 by 12 tile. Therefore, I would have a grout line at 2 feet and therefore perfectly bisecting the tub.

Ok the rub.

How do I bullnose the front edge of the tub deck. Do I widen the deck the width of the purchased bullnose tile so that the main tile still bisects the tub and therefore make the distance between the front edge of the deck to the tub wider by the width of the bullnose compared to the distance between the tub and the back wall?

Or can I or should I grind a bullnose onto the edge of the 12 x 12 tile and keep the deck at 48 inches?

Do the $50 dollar-ish bullnose wheels work for DIYer? Will I go crazy?

Usually there's not enough tiled deck showing to make much difference by the time the tub is set in. I would center the tile width ways and make sure there's no slivers anywhere and call it good. No one will notice if the layout isn't centered from front to back. I doubt your homemade BN will turn out as good as the purchased BN.

Remember that the wider the front part of the deck is, the harder it is to get in.

The bullnose wheels work fine. But realize the tile edge is left pretty rough coming off that wheel and needs to be finished with a few increasingly higher grit carbide grit sandpaper or diamond pads to smooth out the edge.

You said not enough tile showing to make a difference. Well I have chosen an oval tub, so I think there will be more tile than say a rectangular tub. And secondly, the fact that the tub is oval might draw more attention to the fact that the grout line might not line up with the center line of the narrow oval end. Maybe I am to anal. I know I can over think the asthetics for many things and in the end see that it did not matter. Sometime you find they matter a lot.

I agree that having too much tile in front of the tub would make getting in and out of the tub more difficult.

I wish to have a soaking tub set in a raised deck. And I would like the faucets and spout set in the deck, not in through the fiberglass tub itself.

How do I handle the plumbing as far as hooking up the supply lines to the faucets? I can not have any kind of an access panel in from the ajoining shower. Any access panel in from the front would be ugly. The tub is over a crawlspace, does it make any sense to plan on being able to reach up into the tub deck to screw the faucets down and to attach the supply lines? Ever seen this done? Not a lot of room reaching up through a joist bay 16 OC.

Am I missing something? Am I just doomed to a difficult job or an ugly front access panel?

I don't have a complete answer to your question. However, being an access panel fan myself, I'd only forgo it if the plumbing under the deck is "permanent" (as in, e.g. soldered copper connections). If there is serviceable stuff such as O-ring based screw connections, I'd personally prefer having access to this.

Have you researched tileable access panels? You might be able to build your own. I've seen that once at a hotel. It was a section with tile that was removable. I didn't remove it and thus don't know how it was constructed.